This article provides a discussion on adhesively bonded joints and elastic-plastic mathematical model for an adhesive in shear. It discusses the design rules for thin bonded structures and reviews computer programs for the highly loaded stepped-lap joints. The article describes the two-dimensional effects associated with load redistribution around flaws and with damage tolerance. The elastic-isotropic geometric stress-concentration factors and empirically established correlation factors of mechanically fastened joints are discussed. The article provides information on the identification of optimal joint proportions for single-row joints, and the design and analysis of the stronger multirow joints, with particular regard to the bearing-bypass interaction.

This article discusses the material combinations, design details, and fabrication processes considered in the adhesive bonding or melt-fuse interface (amorphous bond) bonding method of joining resin-matrix composites to metals.

Cold pressure welding can be accomplished by deforming in a lap or butt configuration, drawing, extrusion, and rolling. This article provides a discussion on cold pressure lap welding, cold pressure butt welding and cold pressure welding in drawing process with illustrations. It provides information on the combinations of metals that can be successfully cold welded.

This article explores why structural element and subcomponent testing are conducted. It discusses the different types of failure modes in composites, and provides information on the testing methodology, fixturing, instrumentation, and data reporting. The article reviews various standard elements used to characterize composite materials for the various failure modes. Simple structural-element testing under in-plane unidirectional, multidirectional, and combined loading, as well as out-of-plane loading are discussed. Simple bolted and bonded joints, as well as data correlation are reviewed with analytical predictions. The article also provides a list of the ASTM testing standards applicable at the element level of testing for both polymer-matrix composites and metal-matrix composites. It concludes with a discussion on durability and damage tolerance testing.

The structural efficiency of a composite structure is established by its joints and assembly. Adhesive bonding, mechanical fastening, and fusion bonding are three types of joining methods for polymer-matrix composites. This article provides information on surface treatment and the applications of adhesive bonding. It discusses the types of adhesives, namely, epoxy adhesives, epoxy-phenolic adhesives, condensation-reaction PI adhesives, addition-reaction PI adhesives, bismaleimide adhesives, and structural adhesives. The article provides information on fastener selection considerations, including corrosion compatibility, fastener materials and strength, head configurations, importance of clamp-up, interference fit fasteners, lightning strike protection, blind fastening, and sensitivity to hole quality. Types of fusion bonding are presented, namely, thermal welding, friction welding, electromagnetic welding, and polymer-coated material welding.

This article discusses three typical repair types for composite structures: temporary repairs, adhesively bonded repairs, and bolted repairs. It contains a table that lists general design requirements and considerations for the repair of composite structures. The article describes ten steps for an engineering repair approach to effectively restore structural integrity to damaged composite components. Management, validation and certification of repairs are also discussed. The article presents the design guidelines for analyzing the damage and possible strategies for making a repair. It reviews three repair schemes used in repair design analysis, namely, core replacement, adhesively bonded patch, and mechanically fastened patch. The article also emphasizes the various pitfalls and problems in repair design for composite structures.

This article describes low-temperature solid-state welding processes in relation to the interlayer fabrication method, welding method, and welding parameters. The interlayer fabrication method is used to produce vacuum coated interlayers, electrodeposited interlayers, and foil interlayers. The article discusses welding methods, including uniaxial compression and hot isostatic pressing. The article provides information on the effect of base-metal surface finish on the tensile strength of joints solid-state welded using silver interlayers in tabular form and addresses the surface cleaning steps of base-metals.

Oxide - dispersion - strengthened (ODS) materials utilize extremely fine oxide dispersion for strengthening, such as nickel-base alloys or alumina. The processing techniques employed in the production of ODS alloys produce some entrapped gases, which tend to create porosity during welding that can be rectified by suitable designing considerations. This article discusses certain successful design strategies employed in joining ODS alloys in consideration with the grain structure. It further provides a brief discussion on different welding processes involved in joining ODS materials, namely, gas-tungsten arc welding, gas-metal arc welding, electron-beam and laser-beam welding, resistance welding, furnace brazing, friction welding, and explosion welding.

This article describes the process applications, advantages, and limitations of resistance seam welding. The fundamentals of lap seam welding are also reviewed. The article details the types of seam welds, namely, lap seam welds and mash seam welds, and the processing equipment used for lap seam welding. The primary factors used to determine the selection of electrodes, including alloy type and wheel configuration, are reviewed. The article also describes weld quality and process control procedures.

Adhesive bonding is used to assemble composite components into larger structures. Finished components that are damaged during assembly or service are often repaired with adhesive-bonding techniques. This article summarizes criteria for adhesive selection and illustrates typical secondary adhesively bonded joint configurations. It discusses the highly loaded joint considerations of adhesives. The article describes the epoxy adhesives commonly used for the bonding or repair of composite structures. It discusses the surface preparation of composites and metals, and honeycomb processing, including perimeter trimming, mechanical forming, heat forming, core splicing, contouring, and cleaning. The article presents basic steps involved in the adhesive-bonding process and concludes with a discussion on adhesive applications and tooling.

Aluminum, a commonly used base material for brazing, can be easily fabricated by most manufacturing methods, such as machining, forming, and stamping. This article outlines non-heat-treatable wrought alloys typically used as base metals for the brazing process. It highlights chloride-active and fluoride-active types of fluxes that are used for torch, furnace, or dip brazing processes. The article explains the steps to be performed, including the designing of joints, preblaze cleaning, assembling, brazing techniques (dip brazing, furnace and torch brazing, fluxless vacuum brazing), flux removal techniques, and postbraze heat treatment processes. It concludes with information on the safety precautions to be followed during the brazing process.

Adhesive-bonded joints are extensively used in aircraft components and assemblies where structural integrity is critical. This article addresses the problem of how to inspect bonded assemblies so that all discrepancies are identified. It describes several inspection techniques and presents drawbacks and limitations of these techniques. Generic flaw types and flaw-producing mechanisms are listed in a table. The article discusses metal-to-metal defects, adherend defects, honeycomb sandwich defects, repair defects, and in-service defects. It reviews the methods applicable to the inspection of bonded structures, including visual inspection, ultrasonic inspection, X-ray radiography, and neutron radiography. The evaluation and correlation of inspection results are also discussed. The article concludes with information on the effects of ultrasonic wave interference in the ultrasonic inspection of adhesive-bonded joints.

This article describes the types of repair and presents reasons for avoiding damage to a structure or component during repair. It discusses the major standardization issues with emphasis on design, repair materials, repair techniques, and inspection.

A key differentiator between friction stir welding (FSW) and other friction welding processes is the presence of a nonconsumable tool in FSW, often referred to as a pin tool to differentiate it from other tooling associated with the process. This article discusses materials for friction stir welding (FSW) pin tools, various tool geometries that have been used, designs for specific applications, predicting and measuring tool performance, and other considerations in FSW pin tool design. The tool materials include tool steels, superalloys, refractory metals, carbides and ceramics, and superabrasives.

Laser-beam welding (LBW) is a joining process that produces coalescence of material with the heat obtained from the application of a concentrated coherent light beam impinging upon the surface to be welded. This article describes the steps that must be considered when selecting the LBW process. It reviews the individual process variables that influence procedure development of the LBW process. Joint design and special practices related to LBW are discussed. The article concludes with a discussion on the use of consumables and special welding practices.

Adhesive bonding is a proven technology in the manufacture of automotive assemblies, helping carmakers achieve weight reduction goals without compromising body stiffness, crash performance, and noise-vibration-handling characteristics. This article discusses the advantages and limitations of adhesive-bonded aluminum joints and the procedures used to produce them. It addresses surface preparation, the addition of interfacial coatings and primers, and the application of thermoplastic and thermosetting resins. The article examines the nature and role of the various layers that constitute the joint and explains how each contributes to performance. It also discusses adhesive selection factors, joint design, and testing procedures.